Short-term effects of combined pedicle/facet screw fixation plus interbody fusion through the channel-assisted muscle-splitting approach for the treatment of degenerative lumbar spine diseases in the elderly / 中华老年医学杂志

Objective To examine the feasibility and early effects of unilateral pedicle screw fixation in combination with contralateral translaminar facet screw fixation plus interbody fusion through the channel-assisted muscle-splitting approach for the treatment of degenerative lumbar spine diseases in elderly patients.Methods A total of 82 elderly patients with degenerative lumbar spine diseases received treatment between January 2015 and June 2016.Of these patients,25 had lumbar spinal stenosis,42 had degenerative lumbar instability,13 had giant lumbar disc herniation,and two had recurrent lumbar disc herniation;There were 69 cases of single segment and 13 cases of double segment lesions.Perioperative evaluation,imaging evaluation,and clinical evaluation were performed,and surgical complications were analyzed.Results The average length of incision was (2.6 ± 0.4) cm in cases of single segment lesions and (4.4±0.5) cm in cases of two segment lesions.The mean operation time was (98.3±19.6) minutes and peri-operation blood loss was (232.2±25.8) ml.The post-operation height of the intervertebral disc space significantly increased at the last follow-up(P ＜ 0.05);the height of the intervertebral disc space was restored and well maintained with internal fixation showing no loosening,breakage or Cage shift.The post-operation lumbar coronal Cobb angle decreased(P＜0.05)while the sagittal Cobb angle increased(P＜0.05)at the last follow-up.There was no significant difference in the area and grade of the multifidus muscle on MRI 12 months after operation.Seventy-two patients were followed up for 12-18 months (mean =16.8 months),and there were 67 cases of intervertebral fusion (93.1％).The last follow-up showed a Japanese Orthopaedic Association(JOA) score of (25.8 ± 1.7),which was significantly higher than the pre-operation score (10.6±1.3),with an excellence rate of 88.9 ％.The Oswestry Disability Index score was significantly reduced,from (50.9±21.6) at pre-operation to (9.6± 4.8) at the last follow-up.There were 78 patients with primary wound healing,three cases of superficial wound necrosis,one case of dural tear,and one case of nerve root injury.No cardiovascular or cerebrovascular incident was observed during or after operation.Conclusions Combined pedicle/facet screw fixation plus interbody fusion through the channel-assisted muscle-splitting approach shows satisfactory short-term effects when used for the treatment of degenerative lumbar spine diseases in the elderly and possesses advantages such as minimal invasiveness,limited bleeding,quick recovery,high fusion rates and significantly improved clinical outcomes.However,further clinical studies are required to assess its medium-and long-term efficacy.

In Vitro of Quantitative MR Imaging of Early Degenerative Changes in Human Articular Cartilage

PURPOSE: To assess the applicability of quantitative MR microscopy for the detection of glycosaminoglycan (GAG) depletion as an early sign of degeneration in the articular cartilage of humans treated by trypsin. MATERIALS AND METHODS: Four cartilage-bone blocks were obtained from the patient who had suffered from osteoarthritis of the knee and underwent a total knee replacement arthroscopy. Each articular cartilage segment was resected as to a round disk shape (8 mm in diameter) with a remnant of subchondral bone 1 mm in thickness. Four different culture solutions were prepared, and these solutions were 0.2 mg/ml of trypsin solution (group 1), 1 mM of Gd (DTPA) 2-mixed trypsin solution (group 2), phosphate buffered saline (PBS) (group 3), and 1 mM of Gd (DTPA) 2-mixed PBS (group 4). The cartilages were cultured and then MR imagings were performed every hour for 5 hrs, and we continued the additional cultures of 24 hrs, 36 hrs and 48 hrs. Three imaging sequences were used: T1-weighted spin echo (TR/TE, 450/22), proton density turbo spin echo with fat suppression (TR/TE, 3000/25), and CPMG (Carr-Purcell-Meiboom-Gill) (TR/TE/TI, 760/21-168, 360). MR imaging data were analyzed with pixel-by-pixel comparisons in all groups. RESULTS:The GAG loss in the articular cartilage was increased proportionately to the culture duration. Mean changes of T1 relaxation time were 1.2% for group 1, -1.9% for group 3, -54.7% for group 2 and -64.2% for group 4 (p<0.05). When comparing by linear profile on the T1-weighted images, SNR increased and T1 relaxation time decreased for group 2 and 4, as the culture duration increased (p<0.05). On the correlation analysis, there is significant correlation between GAG loss and Gd (DTPA) 2-enhancement for group 2 (p=0.0431), but there was no significant difference for group 4 (p=0.0918). More enhancement with Gd (DTPA) 2-was noted for group 2 than for group 4. Group 2 showed a diffuse enhancement in all the layers of cartilage, but for group 4, prominent enhancement was noted only in the superficial layer. CONCLUSION: Early degenerative changes of the articular cartilage were not noted on the T1-weighted images, turbo spin echo with fat suppresison and T1, T2, or the rho relaxometry by a 1.5 T machine. Only Gd (DTPA) 2- enhancement was useful in the detection of early degeneration of the articular cartilage.

Degenerative Changes of Femoral Articular Cartilage in the Knee: Comparative Study of Specimen Sonography and Pathology

PURPOSE: To determine the sonographic findings of degenerative change in femoral articular cartilage of the knee by comparative study of specimen sonography and pathology. MATERIALS AND METHODS: We obtained 40 specimens of cartilage of the femur (20 medial and 20 lateral condylar) from 20 patients with osteoarthritis of the knee who had undergone total knee replacement. The specimens were placed in a saline-filled container and sonography was performed using a 10MHz linear transducer. Sonographic abnormalities were evaluated at the cartilage surface, within the cartilage, and at the bone-cartilage interface, and were compared with the corresponding pathologic findings. In addition, cartilage thickness was measured at a representative portion of each femoral cartilage specimen and was compared with the thickness determined by sonography. RESULTS: 'Dot 'lesions, irregularity or loss of the hyperechoic line, were demonstrated by sonography at the saline-cartilage interface of 14 cartilages. Pathologic examination showed that these findings corresponded to cleft, detachment, erosion, and degeneration. Irregularities in the hyperechoic line at the bone-cartilage interface were revealed by sonography in eight cartilages and were related to irregularity or loss of tidemark, downward displacement of the cartilage, and subchondral callus formation. Dot lesions, corresponding to cleft and degeneration, were noted within one cartilage. Cartilage thickness measured on specimen and by sonography showed no significant difference (p=0.446). CONCLUSION: Specimen sonography suggested that articular cartilage underwent degenerative histopathological change. Cartilage thickness measured by sonography exactly reflected real thickness.

Sonographic Evaluation of Femoral Articular Cartilage in the Knee

PURPOSE: To investigate the usefulness of sonography for the evaluation of osteoarthritic articular cartilage. MATERIALS AND METHODS:Ten asymptomatic volunteers and 20 patients with osteoarthritis of the knee under-went sonographic evaluation. For this, the knee was maintained of full flexion in order to expose the deep portion of femoral condylar cartilage. Both transverse and longitudinal scans were obtained in standardized planes. Sonographic images of the articular cartilages were analyzed in terms of surface sharpness, echogenicity and thickness, along with associated bone changes. RESULTS: Normal cartilages showed a clearly-defined surface, omogeneously low echogenicity and regular thickness. Among 20 patients, the findings for medial and lateral condyles, respectively, were as follows: poorly defined cartilage surface, 16(80%) and ten(50%); increased echogenicity of cartilage, 17(85%) and 16(80%); cartilage thinning, 16(80%) and 14(70%) (two medial condyles demonstrated obvious cartilage thickening); the presence of thick subchondral hyperechoic bands, five (25%) and four (20%); the presence of osteophytes, 13 (65%) and 12(60%). CONCLUSION: Sonography is a convenient and accurate modality for the evaluation of femoral articular cartilage. In particular, it can be useful for detecting early degenerative cartilaginous change and for studying such change during clinical follow-up.